An electrical wire which can be generally used in a wiring harness for a vehicle is connected to terminals at its both ends. Each of the terminals is received in a terminal-receiving portion of a variety of connector housings, and is capable of being electrically connected to other connectors, other electric junction box, a variety of devices or the like.
Such an electrical wire having both ends to which terminals are connected can be provided in accordance with the following process.
Firstly, an end portion of a core portion (i.e., a conductor portion) is exposed by partly removing an insulating covering from the end portion of the electrical wire. The exposed core portion (i.e., the end portion of the core portion) is disposed such that is abuts against a caulking portion (i.e., an electrical wire-connecting portion) which is disposed in the terminal, and the caulking portion is deformed by means of a terminal-caulking apparatus as disclosed in JP H6-45047 (A) such that the exposed core portion is surrounded by the caulking portion. Finally, the electrical wire is pressed by the caulking portion, and is thus electrically connected to the terminal.
Moreover, the portion in which the terminal and the electrical wire are connected to each other can be partly protected by means of (resin) insert molding for the purpose of enhancing watertight properties therein. For example, see JP 2001-167640 (A).
In this case, after the processing, visual inspection often shows that a foreign material such as fine dust is attached to the portion which is protected by the resin. The presence of the foreign material can be problematic in view of quality control or quality management. In a case where the foreign material is fine fiber, the waterproof properties of the portion sought for protection may be adversely affected. In this case, waterproof reliability can be remarkably reduced or lowered. In addition, the above problems even occur under the circumstances where maintenance, cleaning, and arrangement are properly performed.
In order to solve the above problem, the above operation may be carried out in a clean room. However, the operation inside the clean room remarkably increases cost of manufacturing.